Touch Display Device, Method for Driving the Same, Driving Circuit, Data-Driving Circuit, and Gate-Driving Circuit

ABSTRACT

The present embodiments may provide a touch display device including: a display panel in which a plurality of data lines, a plurality of gate lines, and a plurality of touch electrodes are disposed; a gate-driving circuit configured to drive the plurality of gate lines; a data-driving circuit configured to drive the plurality of data lines; and a touch-driving circuit configured to drive the plurality of touch electrodes while the plurality of data lines and the plurality of gate lines are driven. In this touch display device, while a touch-driving signal swings with a predetermined amplitude, a data signal and a gate signal may also swing with the predetermined amplitude. According to the present embodiments, it is possible to enable high-speed image display and high-speed touch sensing, to perform a display operation and a touch operation simultaneously, and to display an image normally without any image change.

CROSS REFERENCE TO RELATED APPLICATION

This application claims priority from Republic of Korea PatentApplication No. 10-2016-0133165, filed on Oct. 13, 2016, which is herebyincorporated by reference for its entirety.

BACKGROUND OF THE INVENTION 1. Field of Technology

This disclosure relates to a touch display device, a method for drivingthe same, a driving circuit, a data-driving circuit, and a gate-drivingcircuit.

2. Description of the Prior Art

With the development of the information-oriented society, there isgrowing demand for touch display devices for displaying images invarious forms, and accordingly, different types of display devices, suchas a liquid crystal display (LCD) device, a plasma display panel (PDP),and an organic light-emitting display device (OLED), have been used inrecent years.

A display device provides a touch-based input mode that enables a userto easily, intuitively, and conveniently input information or commands,representing a departure from a conventional input mode using buttons,keyboard, and mouse.

To provide the touch-based input mode, it is necessary to recognizewhether a user performs a touch and to accurately detect the coordinatesof the touch.

To this end, a touch-enabled display device is conventionally providedusing one of various touch modes including a resistive mode, acapacitive mode, an electromagnetic induction mode, an infrared mode,and an ultrasonic mode.

Among these various types of touch modes, a capacitive touch mode isfrequently adopted, which detects the occurrence of a touch and thecoordinates of a touch based on a change in capacitance between touchelectrodes or a change in capacitance between a touch electrode and apointer, such as a finger, through a plurality of touch electrodesformed on a touch screen panel.

Meanwhile, attempts have been made to embed a touch screen panelincluding touch electrodes in a display panel in order to improveconvenience of manufacturing a display device and reducing the size of adisplay device.

A conventional touch-sensing-enabled display device performs a displayfunction for image display and a touch function for touch sensing atdifferent times.

When the display function and the touch function are performed atdifferent times, it may be difficult to completely and quickly performthe display function or to completely and quickly perform the touchfunction. That is, high-speed image display and high-speed touch sensingmay not be achieved.

SUMMARY

An aspect of the present embodiments is to provide a touch displaydevice, a method for driving the same, a driving circuit, a data-drivingcircuit, and a gate-driving circuit which enable high-speed imagedisplay and high-speed touch sensing.

Another aspect of the present embodiments is to provide a touch displaydevice, a method for driving the same, a driving circuit, a data-drivingcircuit, and a gate-driving circuit which enable a display operation anda touch operation to be performed simultaneously.

Still another aspect of the present embodiments is to provide a touchdisplay device, a method for driving the same, a driving circuit, adata-driving circuit, and a gate-driving circuit which enable an imageto be displayed normally without any change in the image, whileperforming a display operation and a touch operation simultaneously.

In accordance with an aspect, the present embodiments may provide atouch display device including: a display panel in which a plurality ofdata lines, a plurality of gate lines, and a plurality of touchelectrodes are disposed; a gate-driving circuit configured to output agate signal for driving the plurality of gate lines; a data-drivingcircuit configured to output a data signal for driving the plurality ofdata lines; and a touch-driving circuit configured to output atouch-driving signal in order to drive the plurality of touch electrodeswhile the plurality of data lines and the plurality of gate lines aredriven.

In the touch display device, the touch-driving circuit may output atouch-driving signal swinging with a predetermined amplitude.

In the touch display device, the gate-driving circuit may output a gatesignal having a voltage changed by the amplitude of the touch-drivingsignal during a high-level period of the touch-driving signal.

In the touch display device, the data-driving circuit may output a datasignal having a voltage changed by the amplitude of the touch-drivingsignal during a high-level period of the touch-driving signal.

In accordance with another aspect, the present embodiments may provide amethod for driving a touch display device including a display panel inwhich a plurality of data lines, a plurality of gate lines, and aplurality of touch electrodes are disposed, a gate-driving circuitconfigured to drive the plurality of gate lines, and a data-drivingcircuit configured to drive the plurality of data lines.

The method for driving the touch display device may include: outputtinga touch-driving signal in order to drive the plurality of touchelectrodes while the plurality of data lines and the plurality of gatelines are driven; and detecting occurrence of a touch or coordinates ofa touch based on a signal received through each touch electrode.

In the outputting the touch-driving signal, the touch-driving signal mayswing with a predetermined amplitude. During a high-level period of thetouch-driving signal, a gate signal to drive the gate lines may have avoltage changed by the amplitude of the touch-driving signal, and a datasignal to drive the data lines may have a voltage changed by theamplitude of the touch-driving signal.

In accordance with still another aspect, the present embodiments mayprovide a data-driving circuit for driving a display panel in which aplurality of data lines and a plurality of touch electrodes aredisposed.

The data-driving circuit may include: a Digital-to-Analog Converter(DAC) configured to convert digital image data into an analog voltageand to output the analog voltage, using input gamma voltages; and anoutput buffer configured to output a data signal to the data lines basedon the analog voltage.

The data signal may be output while the touch electrodes are driven andmay have a voltage changed by an amplitude of a touch-driving signalduring a high-level period of the touch-driving signal.

In accordance with yet another aspect, the present embodiments mayprovide a driving circuit for driving a display panel in which aplurality of data lines and a plurality of touch electrodes aredisposed.

The driving circuit may include: a data-driving circuit, configured todrive the plurality of data lines; and a touch-driving circuit,configured to drive the plurality of touch electrodes.

The touch-driving circuit may drive the plurality of touch electrodeswhile the plurality of data lines is driven.

The touch-driving circuit may output a touch-driving signal swingingwith a predetermined amplitude in order to drive the touch electrodes.

The data-driving circuit may output a data signal having a voltagechanged by the amplitude of the touch-driving signal during a high-levelperiod of the touch-driving signal.

In accordance with still another aspect, the present embodiments mayprovide a gate-driving circuit for driving a display panel in which aplurality of gate lines and a plurality of touch electrodes aredisposed.

The gate-driving circuit may include: a shift register, configured togenerate a gate signal synchronized with a clock; a level shifter,configured to convert a signal voltage amplitude of the gate signalgenerated in the shift register; and an output buffer, configured tooutput the gate signal with the converted signal voltage amplitude.

The gate signal output from the output buffer may have a voltage changedby an amplitude of a touch-driving signal during a high-level period ofthe touch-driving signal for driving the touch electrodes.

As described above, the present embodiments may provide a touch displaydevice, a method for driving the same, a driving circuit, a data-drivingcircuit, and a gate-driving circuit which enable high-speed imagedisplay and high-speed touch sensing.

Also, the present embodiments may provide a touch display device, amethod for driving the same, a driving circuit, a data-driving circuit,and a gate-driving circuit which enable a display operation and a touchoperation to be performed simultaneously.

Further, the present embodiments may provide a touch display device, amethod for driving the same, a driving circuit, a data-driving circuit,and a gate-driving circuit which enable an image to be displayednormally without any change in the image, while performing a displayoperation and a touch operation simultaneously.

In addition, the present embodiments may provide a touch display device,a method for driving the same, a driving circuit, a data-drivingcircuit, and a gate-driving circuit which enable a display operation anda touch operation to be simultaneously performed when driving ahigh-resolution display.

BRIEF DESCRIPTION OF THE DRAWINGS

The above and other objects, features and advantages of the presentinvention will be more apparent from the following detailed descriptiontaken in conjunction with the accompanying drawings, in which:

FIG. 1 illustrates a system configuration of a touch display deviceaccording to the present embodiments.

FIG. 2 illustrates a plurality of touch electrodes and signal linesdisposed in a display panel of a touch display device according to thepresent embodiments.

FIG. 3 illustrates a display panel of a touch display device accordingto the present embodiments.

FIG. 4 illustrates one touch electrode and an area thereof in a displaypanel of a touch display device according to the present embodiments.

FIG. 5 is an operational timing diagram of a touch display deviceaccording to the present embodiments.

FIG. 6 illustrates a touch-driving circuit of a touch display deviceaccording to the present embodiments.

FIG. 7 illustrates a structure for transmitting a signal to a touchelectrode in a touch display device according to the presentembodiments.

FIG. 8 illustrates a structure for transmitting a signal to adata-driving circuit and a data line of a touch display device accordingto the present embodiments.

FIG. 9 illustrates an example of a gamma structure for transmitting asignal to a data line in a touch display device according to the presentembodiments.

FIG. 10 illustrates another example of a gamma structure fortransmitting a signal to a data line in a touch display device accordingto the present embodiments.

FIG. 11 illustrates a structure for transmitting a signal to a gate lineof a touch display device according to the present embodiments.

FIG. 12 is a flowchart illustrating a method for driving a touch displaydevice according to the present embodiments.

FIG. 13 illustrates a driving circuit according to the presentembodiments.

FIG. 14 illustrates a gate-driving circuit according to the presentembodiments.

DETAILED DESCRIPTION

Hereinafter, some embodiments of the present disclosure will bedescribed in detail with reference to the accompanying illustrativedrawings. In designating elements of the drawings by reference numerals,the same elements will be designated by the same reference numeralsalthough they are shown in different drawings. Further, in the followingdescription of the present invention, a detailed description of knownfunctions and configurations incorporated herein will be omitted when itmay make the subject matter of the present invention rather unclear.

In addition, terms, such as first, second, A, B, (a), (b) or the likemay be used herein when describing components of the present invention.Each of these terminologies is not used to define an essence, order orsequence of a corresponding component but used merely to distinguish thecorresponding component from other component(s). In the case that it isdescribed that a certain structural element “is connected to”, “iscoupled to”, or “is in contact with” another structural element, itshould be interpreted that another structural element may “be connectedto”, “be coupled to”, or “be in contact with” the structural elements aswell as that the certain structural element is directly connected to oris in direct contact with another structural element.

FIG. 1 illustrates a system configuration of a touch display device 100according to the present embodiments.

Referring to FIG. 1, the touch display device 100 according to thepresent embodiments may include a display panel 110, in which a touchscreen panel (TSP) is embedded, and various types of circuits.

The touch display device 100 according to the present embodiments mayperform a display function of displaying an image and a touch functionof sensing a touch made with a pointer, such as a finger or a pen.

The touch display device 100 according to the present embodimentsperforms the display function and the touch function simultaneously,instead of performing the display function and the touch function atdifferent times.

That is, in the touch display device 100 according to the presentembodiments, a display period for performing the display function mayoverlap or coincide with a touch period for performing the touchfunction.

In the display panel 110 according to the present embodiments, aplurality of data lines (DL) and a plurality of gate lines (GL) for thedisplay function are disposed, and a plurality of sub-pixels (SP),defined by the plurality of data lines (DL) and the plurality of gatelines (GL), may be arranged.

Further, the display panel 110 according to the present embodiments alsoserves as a TSP and thus may include a plurality of touch electrodes(TE) disposed to serve as a touch sensor.

In this sense, the display panel 110 according to the presentembodiments is understood to include the TSP and is also referred to asa “touch-screen-embedded display panel.”

Referring to FIG. 1, the touch display device 100 includes, for thedisplay function, a data driving circuit 120 to output a data signal fordriving the plurality of data lines (DL) arranged in the display panel110 and a gate driving circuit 130 to output a gate signal for drivingthe plurality of gate lines (GL) arranged in the display panel 110.

The touch display device 100 may further include at least one controllerto control operation timing or power supply of the data-driving circuit120 and the gate driving circuit 130.

Referring to FIG. 1, to perform the touch function, the touch displaydevice 100 may include a touch driving circuit 140 to drive theplurality of touch electrodes (TE) embedded in a display panel 110 and atouch processor 150 to determine the occurrence of a touch and/or theposition of a touch based on a signal (TSS) received from a driven touchelectrode (TE).

The touch-driving circuit 140 may supply a touch driving signal (TDS) tothe plurality of touch electrodes (TE) in order to drive the pluralityof touch electrodes (TE).

The touch-driving circuit 140 may receive a Touch-Sensing Signal (TSS)from each touch electrode (TE) supplied with the Touch-Driving signal(TDS).

The TDS transmits the received TSS or sensing data obtained byprocessing the TSS to the touch processor 150.

The touch processor 150 may execute a touch algorithm using the TSS orthe sensing data and may determine the occurrence of a touch and/or theposition of a touch.

As described above, the touch display device 100 according to thepresent embodiments may employ a self-capacitance touch-sensing mode,which detects the occurrence of a touch and/or the position of a touchby detecting a change in capacitance between each touch electrode (TE)and a pointer.

That is, in the touch display device 100 according to the presentembodiment, a TDS is applied to each touch electrode (TE) and a TSS isdetected from each touch electrode (TE).

The touch display device 100 according to the present embodiments mayalso employ a mutual-capacitance touch-sensing mode, in which aplurality of touch electrodes (TE) is classified into a drivingelectrode (also referred to as a Tx electrode) and a sensing electrode(also referred to as an Rx electrode) and a change in capacitancebetween the driving electrode and the sensing electrode is detected byapplying a TDS to the driving electrode and by receiving a TSS by thesensing electrode, thereby detecting the occurrence of a touch and/orthe position of a touch.

However, for the convenience of description, it is assumed in thefollowing description that the touch display device employs theself-capacitance touch-sensing mode.

In the self-capacitance touch-sensing mode, an electrode (referred to asa driving electrode or Tx electrode) to which a TDS is applied to drivea touch and an electrode (referred to as a sensing electrode or Rxelectrode) from which a TSS is detected do not need to be disposedseparately in the touch-screen-embedded display panel 110 according tothe present embodiments, thus facilitating a process for the panel.

The data-driving circuit 120, the gate-driving circuit 130, thetouch-driving circuit 140, and the touch processor 150 described aboveare classified according to functions thereof, and may be separatelyconfigured. If necessary, two or more of the data-driving circuit 120,the gate-driving circuit 130, the touch-driving circuit 140, and thetouch processor 150 may be integrated into a single circuit.

In the present embodiments, one touch electrode (TE) may be larger insize than one sub-pixel SP. That is, one touch electrode (TE) may have asize that is equal to or greater than the size of an area occupied by aplurality of sub-pixels (SP).

For example, one touch electrode (TE, unit touch electrode) may have asize several times to several hundred times larger than that of onesub-pixel (SP).

The ratio between the size of the touch electrode and the size of thesub-pixel may be adjusted in view of touch-sensing efficiency andperformance or in view of the impact of touch sensing on displayoverall.

Further, in the present embodiments, one touch electrode TE may be onewhole electrode (bulk electrode).

One whole electrode corresponding to one touch electrode (TE) may be aplate electrode having no opening therein or may be an electrode havingat least one opening therein.

Alternatively, one touch electrode (TE) may be formed of a plurality ofsub-electrodes arranged in a mesh form and electrically connected.

Alternatively, one touch electrode (TE) may be formed of a plurality ofsub-electrodes arranged in a line form and electrically connected.

As described above, the touch electrodes (TE) may be designed in variousshapes and sizes. Each of the touch electrodes (TE) illustrated in FIG.1 may be understood as a unit area for a touch operation and touchsensing.

Meanwhile, the touch display device 100 according to the presentembodiments may be various types of display devices, such as a liquidcrystal display device and an organic light-emitting display device, interms of display function.

When the touch display device 100 according to the present embodimentsis a liquid crystal display device, the plurality of touch electrodes(TE) may serve as a common electrode to which a common voltage (VCOM) isapplied.

Since the touch display device 100 according to the present embodimentsperforms the display function and the touch function at the same time, aTDS applied to the plurality of touch electrodes (TE) for touch sensingalso serves as a common voltage (VCOM) for the display function.

Accordingly, the touch display device 100 according to the presentembodiments simultaneously drives the plurality of touch electrodes(TE). That is, a TDS is applied to all of the touch electrodes (TE).

However, the touch processor 150 detects the occurrence of a touchand/or the coordinates of a touch by individually using a TSS receivedfrom each touch electrode (TE).

As described above, since the touch display device 100 according to thepresent embodiments performs the display function and the touch functionsimultaneously, a TDS applied to all of the plurality of touchelectrodes (TE) serves as a common voltage (VCOM) to form liquid crystalcapacitance (Clc) together with a pixel voltage (data voltages) appliedto a pixel electrode of the plurality of sub-pixels (SP).

As described above, when the plurality of touch electrodes (TE) alsoserves as a common electrode to which the common voltage (VCOM) iscommonly applied, the plurality of touch electrodes (TE) may beelectrically connected inside or outside of the touch-driving circuit140.

FIG. 2 illustrates a plurality of touch electrodes (TE) and signal lines(SL) disposed in a display panel 110 of a touch display device 100according to the present embodiments. Here, FIG. 2 illustrates aself-capacitance touch-sensing structure.

Referring to FIG. 2, a plurality of signal lines (SL) for electricallyconnecting the plurality of touch electrodes (TE) and a touch-drivingcircuit 140 may be disposed in the display panel 110.

In the self-capacitance touch-sensing structure, the plurality of touchelectrodes (TE) does not overlap each other and is not electricallyconnected within the display panel 110.

Further, the plurality of signal lines (SL) does not overlap each otherand is not electrically connected within the display panel 110.

FIG. 3 illustrates a display panel 110 of a touch display device 100according to the present embodiments.

Referring to FIG. 3, one touch electrode (TE) is formed to correspond toan area of X*Y sub-pixels (SP).

As described above, the touch display device 100 according to thepresent embodiments simultaneously performs a display function for imagedisplay and a touch function for touch sensing.

That is, the touch display device 100 according to the presentembodiments simultaneously conducts a display operation for imagedisplay and a touch operation for touch sensing.

The touch display device 100 drives a data line (DL), a gate line (GL),and a display-related electrode, such as a common electrode, whenperforming a display operation.

In the touch display device 100, a plurality of touch electrodes (TE)may be a common electrode to form liquid crystal capacitance (Clc)together with a pixel electrode (PXL).

As described above, the touch electrode (TE) serving as a touch sensoris also used as a common electrode to which a common voltage (VCOM)needed for a display operation is applied, thereby simplifying apanel-manufacturing process, reducing the thickness of the panel, andenabling efficient manufacture of the touch-screen-embedded displaypanel 110.

To display an image, a color expressed in a sub-pixel (SP) is determinedbased on liquid crystal capacitance (Clc), which is the capacitancebetween the touch electrode (TE) and the pixel electrode (PXL).

A color expressed in a sub-pixel (SP) is determined based on a voltagedifference (=VDATA−VCOM=VDATA−TDS) between a data voltage (VDATA)supplied to a pixel electrode (PXL) of the sub-pixel (SP) through thedata line (DL) and a common voltage (VCOM) corresponding to a TDSapplied to the touch electrode (TE).

The data voltage (VDATA) supplied to the data line (DL) is transmittedto the pixel electrode (PXL) through a transistor (TR) in the connectedsub-pixel (SP).

Here, in the transistor TR, a gate electrode is connected to the gateline (GL), a source electrode (or drain electrode) is connected to thedata line (DL), and the drain electrode (or source electrode) isconnected to the pixel electrode (PXL).

For touch sensing, a TDS is applied to the touch electrode (TE).

Since the touch operation and the display operation are simultaneouslyperformed, the TDS, which also serves as a common voltage (VCOM), isapplied to all of the touch electrodes (TE).

Accordingly, finger capacitance (Cf) is formed between the touchelectrode TE disposed at a position where the user makes a touch and theuser's pointer (for example, a finger and a pen).

Here, various parasitic capacitances (Cgd, Cgt, Cdt, and Ctt) may beformed in the display panel 110.

Parasitic capacitance Cgd may be formed between the gate line (GL) andthe data line (DL); parasitic capacitance Cgt may be formed between thegate line (GL) and the touch electrode (TE); parasitic capacitance Cdtmay be formed between the data line (DL) and the touch electrode (TE);and parasitic capacitance Ctt may be formed between two adjacent touchelectrodes (TE).

Since the TDS is applied to all the touch electrodes (TE), no parasiticcapacitance (Ctt) may be formed between two adjacent touch electrodes(TE).

These various parasitic capacitances (Cgd, Cgt, Cdt and Ctt) mayincrease a resistor-capacitor load (RC load) and may affect the fingercapacitance (Cf) formed between the touch electrodes (TE) and the user'spointer (for example, a finger or a pen), thus reducing the accuracy oftouch sensing.

Therefore, for touch sensing and image display, while the TDS, whichalso serves as a common voltage (VCOM), is applied to all the touchelectrodes (TE), the TDS or a corresponding signal may also be appliedto some or all of data lines (DL) and some or all of gate lines (GL).

Accordingly, for touch sensing and video display, it is possible toprevent unnecessary parasitic capacitances (Cgd, Cgt, Cdt, and Ctt) frombeing formed while the TDS, which also serves as a common voltage(VCOM), is applied to all the touch electrodes (TE), regardless of theposition at which a touch is made or even if no touch is made at anyposition.

Hereinafter, in order to improve both image display performance andtouch-sensing performance, an efficient method in which a touch displaydevice 100 simultaneously performs a display operation for image displayand a touch operation for touch sensing is described in detail.

FIG. 4 illustrates one touch electrode (TE) and an area thereof in adisplay panel 110 of a touch display device 100 according to the presentembodiments.

FIG. 4 shows one touch electrode (TE) and three sub-pixels (SP1, SP2,and SP3) among X*Y sub-pixels (SP) disposed in an area of the touchelectrode in order to describe an efficient method in which the touchdisplay device 100 simultaneously performs a display operation for imagedisplay and a touch operation for touch sensing.

Referring to FIG. 4, the three sub-pixels (SP1, SP2, and SP3) areconnected to one data line (DL).

Accordingly, a sub-pixel SP1 is supplied with a data signal VDATA1through the data line (DL). A sub-pixel SP2 is supplied with a datasignal VDATA2 through the data line (DL). A sub-pixel SP3 is suppliedwith a data signal VDATA3 through the data line (DL).

Referring to FIG. 4, the three sub-pixels (SP1, SP2 and SP3) areconnected to three gate lines (GL1, GL2 and GL3), respectively.

Accordingly, the sub-pixel SP1 is supplied with a gate signal through agate line GL1. The sub-pixel SP2 is supplied with a gate signal througha gate line GL2. The sub-pixel SP3 is supplied with a gate signalthrough a gate line GL3.

Referring to FIG. 4, the one touch electrode (TE) is connected to onesignal line (SL) and is supplied with a TDS.

FIG. 5 is an operational timing diagram of a touch display device 100according to the present embodiments.

Referring to FIG. 5, the touch display device 100 simultaneouslyperforms a display operation for image display and a touch operation fortouch sensing.

That is, the touch display device 100 may perform a touch operation fordetecting the occurrence of a touch and/or the coordinates of a touch inthe entire area of a screen one, two, or more times during the time ofone frame in which a display operation for image display is performed.

Thus, a touch-driving circuit 140 may output a TDS to drive a pluralityof touch electrodes (TE) while a plurality of data lines (DL) and aplurality of gate lines (GL) are driven, that is, during a displayoperation period.

The touch-driving circuit 140 may output a TDS that swings at apredetermined amplitude (VLFD).

Accordingly, the TDS may be a pulse signal having the predeterminedamplitude (VLFD).

Here, a low-level voltage of the TDS may correspond to a DC voltagevalue of the common voltage (VCOM), and a high-level voltage of the TDSmay be a voltage higher than the low-level voltage by the predeterminedamplitude (VLFD).

Referring to FIG. 5, a gate-driving circuit 130 may output a gate signalhaving a voltage (VGL+VLFD or VGH+VLFD) changed (for example, increased)by the amplitude (VLFD) of the TDS during a high-level period (that is,a pulse generation period) of the TDS.

Referring to FIG. 5, a data-driving circuit 120 may output a data signalhaving a voltage (VDATA1+VLFD, VDATA2+VLFD, or VDATA3+VLFD) increased bythe amplitude (VLFD) of the TDS during the high-level period (that is,the pulse generation period) of the TDS.

According to the above description, although the touch electrode (TE)serves as a touch sensor to which a TDS in the form of a pulse signal isapplied, instead of a DC voltage, for touch sensing, and also serves asa common electrode needed for display operation, the data signal and thegate signal swing according to the amplitude (VLFD) of the TDS, therebyperforming the display operation normally while a touch operation isperformed.

Referring to FIG. 5, during the high-level period (1T) of the TDS, thegate-driving circuit 130 may output a gate signal having a voltage(VGH+VLFD) of a turn-on gate voltage (VGH) plus the amplitude (VLFD) ofthe TDS to a gate line (GL) corresponding to a turn-on time among theplurality of gate lines (GL).

During the high-level period (1T) of the TDS, the gate-driving circuit130 may output a gate signal having a voltage (VGL+VLFD) of a turn-offgate voltage (VGL) plus the amplitude (VLFD) of the TDS to a gate line(GL) corresponding to a turn-off time among the plurality of gate lines(GL).

For example, when a gate line GL1 corresponds to the turn-on time andgate lines GL2 and GL3 correspond to the turn-off time, a gate signalhaving a voltage (VGH+VLFD) of the turn-on gate voltage (VGH) plus theamplitude (VLFD) of the TDS is applied to the gate line GL1 during thehigh-level period (1T) of the TDS applied to the touch electrode (TE).Here, a gate signal having a voltage (VGL+VLFD) of the turn-off gatevoltage (VGL) plus the amplitude (VLFD) of the TDS may be applied to thegate lines GL2 and GL3.

Accordingly, a voltage difference between the TDS and the gate signaloutput to the gate line (GL) corresponding to the turn-on time among thegate lines (GL) during the high-level period (1T) of the TDS is theturn-on gate voltage (VGH), and a voltage difference between the TDS andthe gate signal output to the gate line (GL) corresponding to theturn-off time among the gate lines (GL) is the turn-off gate voltage(VGL).

As described above, by increasing the gate signal by the amplitude(VLFD) of the TDS, a voltage difference between the gate line (GL) andthe touch electrode (TE) may be eliminated, thus preventing parasiticcapacitance (Cgt) from being formed between the gate line (GL) and thetouch electrode (TE) and enabling a gate operation for image display tobe performed normally.

Meanwhile, the high-level period (1T) of the TDS may be equal to orshorter than one horizontal duration (1H), that is, a period duringwhich a voltage to turn on a transistor of a corresponding sub-pixel isto be applied.

In another aspect, the gate-driving circuit 130 may output a pluralityof pulses to one gate line during a period of one frame.

For example, referring to FIG. 5, during a period of one frame, onepulse with a high-level voltage of VGH+VLFD and two pulses with ahigh-level voltage of VGL+VLFD are output to the gate line GL1.

Here, the one pulse with the high-level voltage of VGH+VLFD is a gatepulse for actually turning on the gate line GL1.

That is, among a plurality of pulses applied to one gate line during aperiod of one frame, one pulse has a voltage (VGH+VLFD) of the turn-ongate voltage (VGH) plus the amplitude (VLFD) of the TDS, and the otherpulses have a voltage (VGL+VLFD) of the turn-off gate voltage (VGL) plusthe amplitude (VLFD) of the TDS.

Referring to FIG. 5, the data-driving circuit 120 may output a datasignal having a voltage (VDATA1+VLFD, VDATA2+VLFD, or VDATA3+VLFD) of adata voltage (VDATA1, VDATA2, or VDATA3) corresponding to input digitalimage data plus the amplitude VLFD of the TDS during the high-levelperiod (1T) of the TDS.

For example, when a data voltage, obtained when digital image data to besupplied to the sub-pixel SP1 of FIG. 4 is directly changed into ananalog voltage, is VDATA1, a data signal actually supplied to thesub-pixel SP1 is VDATA1+VLFD according to the present embodiments.

Likewise, when a data voltage, obtained when digital image data to besupplied to the sub-pixel SP2 of FIG. 4 is directly changed into ananalog voltage, is VDATA2, a data signal actually supplied to thesub-pixel SP2 is VDATA2+VLFD according to the present embodiments.

When a data voltage obtained when digital image data to be supplied tothe sub-pixel SP3 of FIG. 4 is directly changed into an analog voltageis VDATA3, the data signal actually supplied to the sub-pixel SP3 isVDATA3+VLFD according to the present embodiments.

According to the above description, a voltage difference between thedata signal (VDATA1+VLFD, VDATA2+VLFD, or VDATA3+VLFD) and the voltage(VLFD) of the TDS during the high-level period (1T) of the TDS maycorrespond to the original data voltage (VDATA1, VDATA2, or VDATA3) forimage display.

As described above, by increasing the data signal by the amplitude(VLFD) of the TDS, the voltage difference between the data line (DL) andthe touch electrode (TE) may be eliminated, thus preventing parasiticcapacitance (Cdt) from being formed between the data line (DL) and thetouch electrode (TE) and enabling a data operation for image display tobe performed normally.

In the case of performing an operation according to the operationaltiming shown in FIG. 5, no image difference due to the display operationoccurs, even during touch sensing.

The foregoing operation is described again with reference to thefollowing equations.

When the touch electrode (TE) pulses by the amplitude (VLFD) to performtouch sensing during one horizontal time (1H), the gate line (GL) andthe data line (DL) also pulse by the amplitude (VLFD).

As such, pulsing of the gate line (GL), the data line (DL), anothertouch electrode (TE) not performing sensing, or other neighboringelectrodes by the amplitude (VLFD) is referred to as Load-Free Driving(LFD).

Here, a change in the amount of electric charges charged correspondingto liquid crystal capacitance (Clc) is expressed by Equation 1 below.

Qlc1=Clc×Vlc=Clc×(VDATA−VCOM)

Qlc2=Clc×Vlc=Clc×[(VDATA+VLFD)−(VCOM+VLFD)]=Clc×(VDATA−VCOM)  [Equation1]

In Equation 1, Qlc1 denotes the amount of electric charges chargedcorresponding to liquid crystal capacitance (Clc) in the absence of LFD,and Qlc2 denotes the amount of electric charges charged corresponding toliquid crystal capacitance (Clc) in the presence of LFD.

In Equation 1, Clc denotes the liquid crystal capacitance between apixel electrode (PXL) and a touch electrode (TE), as a common electrode,and Vlc denotes a potential difference between the opposite ends of theliquid crystal capacitance.

In Equation 1, VDATA denotes the voltage of a data signal applied to thepixel electrode (PXL), and VCOM denotes a common voltage, whichcorresponds to a low-level voltage of a TDS applied to the touchelectrode (TE). VLFD corresponds to a high-level voltage of the TDS.

Equation 1 shows that the same amount of electric charges is chargedregardless of whether no LFD is performed or LFD is performed tosimultaneously perform a display operation and a touch operation.

Since the change in the amount of electric charges corresponding to theliquid crystal capacitance (Clc) leads to an image change, no change inthe amount of electric charges means that there is no image change eventhough a touch operation and a display operation are simultaneouslyperformed according to LFD.

Also, as shown in Equation 2, although a touch operation and a displayoperation are simultaneously performed according to LFD, there is nochange in the electric charge amount of capacitance (Cgd) between thegate line (GL) and the data line (DL).

Qgd1=Cgd×Vgd=Cgd×(VGATE−VDATA)

Qgd2=Cgd×Vgd=Cgd×[(VGATE+VLFD)−(VDATA+VLFD)]=Cgd×(VGATE−VDATA)  [Equation2]

In Equation 2, Qgd1 denotes the amount of electric charges chargedcorresponding to the capacitance (Cgd) between the gate line (GL) andthe data line (DL) in the absence of LFD, and Qlc2 denotes the amount ofelectric charges charged corresponding to the capacitance (Cgd) betweenthe gate line (GL) and the data line (DL) in the presence of LFD.

In Equation 2, Cgd denotes the capacitance between the gate line (GL)and the data line (DL), and Vgd denotes a potential difference betweenthe opposite ends of the capacitance between the gate line (GL) and thedata line (DL).

In Equation 2, VGATE denotes the voltage of a gate signal applied to thegate line (GL), VDATA denotes the voltage of a data signal applied tothe data line (DL), and VLFD corresponds to the high-level voltage ofthe TDS.

Equation 2 shows that the same amount of electric charges is chargedregardless of whether no LFD is performed or LFD is performed tosimultaneously perform a display operation and a touch operation.

When Cgd, Cgt, Cdt, Ctt, and Clc, shown in FIG. 3, are calculated usingEquations 1 and 2, there is no change in the amount of electric chargeseven though LFD is performed to simultaneously perform a displayoperation and a touch operation.

When a user touches a specific touch electrode (TE) serving as a commonelectrode, finger capacitance (Cf) between a pointer, such as a finger,and the touch electrode (TE) is formed.

When LFD is performed to simultaneously perform a display operation anda touch operation, a change in the amount of electric charges chargedcorresponding to the finger capacitance (Cf) is as follows.

Qfinger1=Cf×Vtf=Cf×(VCOM−Vfinger)

Qfinger2=Cf×Vtf=Cf×[(VCOM+VLFD)−Vfinger)]

ΔQfinger=Cf×Vtf=Cf×VLFD  [Equation 3]

In Equation 3, Qfinger1 denotes the amount of electric charges chargedcorresponding to the finger capacitance (Cf) in the absence of LFD, andQfinger2 denotes the amount of electric charges charged corresponding tothe finger capacitance (Cf) in the presence of LFD.

In Equation 3, Cf denotes the finger capacitance between the pointer,such as a finger, and the touch electrode (TE), and Vtf denotes apotential difference between the pointer, such as a finger, and thetouch electrode (TE).

In Equation 3, VCOM denotes a common voltage, which corresponds to alow-level voltage of a TDS applied to the touch electrode (TE). VLFDcorresponds to a high-level voltage of the TDS. Vfinger corresponds tothe voltage of the pointer, such as a finger.

According to Equation 3, a change in the amount of electric charges(ΔQfinger) may be determined according to the high-level voltage (VLFD)of the TDS and the finger capacitance (Cf).

FIG. 6 illustrates a touch-driving circuit 140 of a touch display device100 according to the present embodiments.

Referring to FIG. 6, the touch-driving circuit 140 may include anamplifier 610, an integrator 620, a sample-and-hold circuit 630, and ananalog-to-digital converter (ADC) 640.

The amplifier 610 outputs a TDS input from a positive terminal to anegative terminal.

The TDS output to the negative terminal of the amplifier 610 is appliedto a touch electrode (TE) disposed in a display panel 110.

When the TDS is applied to the touch electrode (TE), finger capacitance(Cf) is formed on the touch electrode (TE) in response to the occurrenceof a touch.

As the finger capacitance Cf is formed, a signal (TSS) is input as a TDSthrough the touch electrode (TE), and electric charges are chargedcorresponding to feedback capacitance (Cfb) connected to the negativeterminal of the amplifier 610 and an output terminal. The amount ofcharged electric charges changes depending on a touch.

The integrator 620 integrates a signal output from the amplifier 610 apredetermined number of times and outputs the signal. Thesample-and-hold circuit 630 samples and stores the signal output fromthe integrator 620.

The ADC 640 reads the signal stored by the sample-and-hold circuit 630,converts the signal into a digital sensing value, and outputs thesensing value to a touch processor 150.

The touch processor 150 calculates the occurrence of a touch and/or thecoordinates of a touch based on sensing values.

Hereinafter, a structure in which a TDS, a data signal, a gate signal,and the like, described with reference to FIG. 5, are transmitted to acorresponding electrode or a wire will be described.

FIG. 7 illustrates a structure for transmitting a signal to a touchelectrode (TE) in a touch display device 100 according to the presentembodiments.

Referring to FIG. 7, all touch electrodes (TE) are driven at the sametime, among which, at a specific time, only some touch electrodes (TEs)are driven for touch sensing and the other touch electrodes (TEo) aredriven to prevent the formation of parasitic capacitance (Ctt, Cgt, orCdt).

Each of the touch electrodes (TEs and TEo) may be connected to bothcircuit components 710 a and 610 for receiving a TDS for touch sensingand to a circuit component 710 b for receiving a TDS to prevent theformation of parasitic capacitance (Ctt, Cgt, or Cdt).

A TDS for touch sensing is output from a touch power IC (TPIC) 700 andis applied to the touch electrodes (TEs) driven for touch sensing viathe amplifier 610 and a first multiplexer 710 a.

A TDS for preventing the formation of parasitic capacitance is outputfrom the TPIC 700 and is applied to the touch electrodes (TEo) driven toprevent the formation of parasitic capacitance through a secondmultiplexer 710 b.

Here, the TDS for preventing the formation of parasitic capacitance isalso referred to as a Load-Free Driving Signal (LFDS).

FIG. 8 illustrates a structure for transmitting a signal to adata-driving circuit 120 and a data line (DL) of a touch display device100 according to the present embodiments.

Referring to FIG. 8, the data-driving circuit 120 of the touch displaydevice 100 according to the present embodiments includes one or morelatches 810 to receive and store digital image data from a controller orthe like, a digital-to-analog Converter (DAC) 820 to convert digitalimage data output from the latch 810 into an analog voltage and tooutput the analog voltage using input gamma voltages (Vgam1, Vgam2, . .. , and Vgam256), and an output buffer 830 to output a data signal tothe data line (DL) on the basis of the analog voltage.

The data signal output from the output buffer 830 to the data line (DL)is output while a touch electrode (TE) is driven and has a voltageincreased by the amplitude (VLFD) of a TDS during a high-level period(1T) of the TDS.

As described above, by increasing the data signal by the amplitude(VLFD) of the TDS, the voltage difference between the data line (DL) andthe touch electrode (TE) may be eliminated, thus preventing parasiticcapacitance (Cdt) from being formed between the data line (DL) and thetouch electrode (TE) and enabling a data operation for image display tobe performed normally.

Referring to FIG. 8, the gamma voltages (Vgam1, Vgam2, . . . , andVgam256) may swing according to the amplitude (VLFD) of the TDS.

Accordingly, the analog voltage output from the DAC 820 and the datasignal output from the output buffer 830 may also swing according to thegamma voltages (Vgam1, Vgam2, . . . , and Vgam256).

As such, as the gamma voltages (Vgam1, Vgam2, . . . , Vgam256) used forthe generation of the data signal swing in accordance with the swing ofthe TDS, the data signal outputted from the data-driving circuit 120also swings in accordance with the swing of the TDS.

Accordingly, a voltage difference between the data line (DL) and thetouch electrode (TE) may be eliminated, thus preventing the formation ofparasitic capacitance (Cdt) between the data line (DL) and the touchelectrode (TE).

The gamma voltages (Vgam1, Vgam2, . . . , and Vgam256) swinging with theamplitude (VLFD) of the TDS may be generated and output from a gammageneration circuit 800.

The gamma generation circuit 800 may be included in the data-drivingcircuit 120, or may be disposed outside the data-driving circuit 120.

The above-mentioned gamma voltages are also referred to as a gammareference voltage or a gamma reference.

Two examples of the gamma generator circuit 800 are described below.

FIG. 9 illustrates an example of a gamma structure for transmitting asignal to a data line (DL) in a touch display device 100 according tothe present embodiments.

Referring to FIG. 9, a gamma generation circuit 800 may include afirst-stage amplifier circuit 910 and a first-stage resistor string 920.

The first-stage amplifier circuit 910 may include: an upper amplifier911 having an input node to which an upper DC voltage (VTOP) is input,coupled with a signal (GS) swinging with the amplitude (VLFD) of theTDS, through a capacitor (CC); and a lower amplifier 912 having an inputnode to which a lower DC voltage (VBOT) is input, coupled with a signal(GS) swinging with the amplitude (VLFD) of the TDS through the capacitor(CC).

A signal input to a positive input terminal of the upper amplifier 911is a signal that is obtained by coupling the upper DC voltage (VTOP)with the signal (GS) swinging with the amplitude (VLFD) of the TDS andthat swings with the amplitude (VLFD) of the TDS.

A signal input to a positive input terminal of the lower amplifier 912is a signal that is obtained by coupling the lower DC voltage (VBOT)with the signal (GS) swinging with the amplitude (VLFD) of the TDS andthat swings with the amplitude (VLFD) of the TDS.

The first-stage resistor string 920 may be connected to an output nodeof the upper amplifier 911 and an output node of the lower amplifier912.

The gamma voltages (Vgam1, Vgam2, . . . , and Vgam256) may be output atresistor connection points in the first-stage resistor string 920.

Here, the gamma voltages (Vgam1, Vgam2, . . . , and Vgam256) swing withthe amplitude (VLFD) of the TDS.

Using the gamma generation circuit 800 illustrated in FIG. 9, it ispossible to generate gamma voltages (Vgam 1, Vgam 2, . . . , and Vgam256) which swing in a manner similar or identical to that of the TDS,using only a simple circuit configuration.

FIG. 10 illustrates another example of a gamma structure fortransmitting a signal to a data line (DL) in a touch display device 100according to the present embodiments.

Referring to FIG. 10, a gamma generation circuit 800 may include afirst-stage amplifier circuit 910, a first-stage resistor string 920, asecond-stage amplifier circuit 1010, and a second-stage resistor string1020.

The first-stage amplifier circuit 910 may include: an upper amplifier911 having an input node to which an upper DC voltage (VTOP) is input,coupled with a signal (GS) swinging with the amplitude (VLFD) of theTDS, through a capacitor (CC); and a lower amplifier 912 having an inputnode to which a lower DC voltage (VBOT) is input, coupled with a signal(GS) swinging with the amplitude (VLFD) of the TDS through the capacitor(CC).

A signal input to a positive input terminal of the upper amplifier 911is a signal that is obtained by coupling the upper DC voltage (VTOP)with the signal (GS) swinging with the amplitude (VLFD) of the TDS andthat swings with the amplitude (VLFD) of the TDS.

A signal input to a positive input terminal of the lower amplifier 912is a signal obtained by coupling the lower DC voltage (VBOT) with thesignal (GS) swinging with the amplitude (VLFD) of the TDS and thatswings with the amplitude (VLFD) of the TDS.

The first-stage resistor string 920 may be connected to an output nodeof the upper amplifier 911 and an output node of the lower amplifier912.

The second-stage amplifier circuit 1010 may include a plurality ofamplifiers having an input node connected to resistor connection pointsin the first-stage resistor string 920.

The second-stage resistor string 1020 may be connected to output nodesof the amplifiers included in the second-stage amplifier circuit 1010.

Gamma voltages (Vgam1, Vgam2, . . . , and Vgam256) may be output atresistor connection points in the second-stage resistor string 1020.

Referring to FIG. 10, the first-stage amplifier circuit 910 and thefirst-stage resistor string 920 correspond to a coarse gamma generationpart, and the second-stage amplifier circuit 1010 and the second-stageresistor string 1020 correspond to a fine gamma generation part.

The coarse gamma generation part generates a primary gamma voltage(gamma reference), and the fine gamma generation part generates a finegamma voltage using the primary gamma voltage generated in the coarsegamma generation part, adjusting the gamma voltage by tuning aresistance value.

The coarse gamma generation part generates a 4-bit coarse gamma voltage(gamma reference).

The fine gamma generation part generates a 4-bit fine gamma voltage(gamma reference).

Accordingly, the finally outputted gamma voltages (Vgam1, . . . , andVgam256) correspond to an 8-bit gamma reference.

The coarse gamma generation part generates an important portion of agamma curve and outputs a fixed value. The fine gamma generation partoutputs a variable value.

It is merely an example that the coarse gamma generation part generatesthe 4-bit coarse gamma voltage (gamma reference) and the fine gammageneration part generates the 4-bit fine gamma voltage (gammareference). Instead, the generation parts may generate gamma voltages ofdifferent bits.

Using the gamma generation circuit 800 illustrated in FIG. 10, it ispossible to precisely generate the gamma voltages (Vgam1, Vgam2, . . . ,and Vgam256) swinging in a manner similar or identical to that of theTDS.

FIG. 11 illustrates a structure for transmitting a signal to a gate line(GL) of a touch display device 100 according to the present embodiments.

Referring to FIG. 11, a gate-driving circuit 130 may output, through aswitching circuit 1100, a gate signal based on one selected from among aturn-on gate voltage (VGH), a voltage of the turn-on gate voltage (VGH)plus the amplitude (VLFD) of a TDS, a turn-off gate voltage (VGL), and avoltage of the turn-off gate voltage (VGL) plus the amplitude (VLFD) ofthe TDS.

As described above, the gate-driving circuit 130 may generate a gatesignal swinging in accordance with the swing of a TDS.

Referring to FIG. 11, the turn-on gate voltage (VGH), the voltage of theturn-on gate voltage (VGH) plus the amplitude (VLFD) of the TDS, theturn-off gate voltage (VGL), and the voltage of the turn-off gatevoltage (VGL) plus the amplitude (VLFD) of the TDS may be supplied froma power management IC (PMIC) 1110.

The gate-driving circuit 130 may include a level shifter.

Further, the gate-driving circuit 130 may be configured as agate-in-panel (GIP) type.

Hereinafter, a method for driving the foregoing touch display device 100is briefly described.

FIG. 12 is a flowchart illustrating a method for driving a touch displaydevice 100 according to the present embodiments.

Referring to FIG. 12, the touch display device 100 includes: a displaypanel 110 in which a plurality of data lines (DL), a plurality of gatelines (GL), and a plurality of touch electrodes (TE) are disposed; agate-driving circuit 130 to drive the plurality of gate lines (GL); anda data-driving circuit 120 to drive the plurality of data lines (DL).

The method for driving the touch display device 100 may includeoutputting a TDS to drive the plurality of touch electrodes (TE) whilethe plurality of data lines (DL) and the plurality of gate lines (GL)are driven (S1210) and detecting the occurrence of a touch or thecoordinates of a touch based on a signal received through each touchelectrode (TE) (S1220).

In operation S1210, the TDS swings with a predetermined amplitude(VLFD).

Further, a gate signal to drive the gate lines (GL) swings in accordancewith the swing of the TDS.

Accordingly, the gate signal to drive the gate lines (GL) has a voltageincreased by the amplitude (VLFD) of the TDS during a high-level period(T1) of the TDS.

Further, a data signal to drive the data lines (DL) swings in accordancewith the swing of the TDS.

Accordingly, the data signal to drive the data lines (DL) has a voltageincreased by the amplitude (VLFD) of the TDS.

Using the driving method, although the touch electrode (TE) serves as atouch sensor to which a TDS in the form of a pulse signal is applied,instead of a DC voltage, for touch sensing, and also serves as a commonelectrode needed for a display operation, the data signal and the gatesignal swing according to the amplitude (VLFD) of the TDS, whereby thedisplay operation is performed normally while a touch operation isperformed.

FIG. 13 illustrates a driving circuit 1300 according to the presentembodiments.

The data-driving circuit 120 and the touch-driving circuit 140 describedabove may be configured in one integrated circuit.

For example, as illustrated in FIG. 13, one data-driving circuit 120 andtwo touch-driving circuits 140 may be configured in one integratedcircuit.

Referring to FIG. 13, the driving circuit 1300 to drive a display panel110 in which a plurality of data lines (DL) and a plurality of touchelectrodes (TE) are disposed may include a data-driving circuit 120 todrive the plurality of data lines (DL) and a touch-driving circuit 140to drive the plurality of touch electrodes (TE).

The touch-driving circuit 140 may drive the plurality of touchelectrodes (TE) while the plurality of data lines (DL) is driven.

The touch-driving circuit 140 may output a TDS swinging with apredetermined amplitude (VLFD) in order to drive the touch electrodes(TE).

The data-driving circuit 120 may output a data signal having a voltageincreased by the amplitude (VLFD) of the TDS during a high-level periodof the TDS.

As described above, both a data operation and a touch operation may beprovided through the driving circuit 1300 configured as one integratedcircuit. Further, using the driving circuit 1300, the data signal swingswith the amplitude (VLFD) of the TDS, and thus a data operation forimage display may be performed normally while a touch operation isperformed.

Hereinafter, the foregoing gate-driving circuit 130 is brieflydescribed.

FIG. 14 illustrates a gate-driving circuit 130 according to the presentembodiments.

Referring to FIG. 14, the gate-driving circuit 130 according to thepresent embodiments may include a shift register 1410 to generate a gatesignal synchronized with a clock, a level shifter 1420 to convert thesignal voltage amplitude of the gate signal generated in the shiftregister 1410 into a level for a gate operation, and an output buffer1430 to output the gate signal with the converted signal voltageamplitude.

The gate signal output from the output buffer 1430 may have a voltageincreased by the amplitude (VLFD) of a TDS during a high-level period(1T) of the TDS to drive a touch electrode (TE).

Using the gate-driving circuit 130, it is possible to generate andoutput a gate signal swinging according to a TDS. Accordingly, a voltagedifference between a gate line (GL) and a touch electrode (TE) may beeliminated, thus preventing parasitic capacitance (Cgt) from beingformed between the gate line (GL) and the touch electrode (TE) andenabling a gate operation for image display to be performed normally.

The gate-driving circuit 130 may further include a switching circuit1100 that selects one of a turn-on gate voltage (VGH), a voltage(VGH+VLFD) of the turn-on gate voltage (VGH) plus the amplitude (VLFD)of aTDS, a turn-off gate voltage (VGL), and a voltage (VGL+VLFD) of theturn-off gate voltage (VGL) and the amplitude (VLFD) of the TDS, andsupplies the selected voltage to the shift register 1410.

The switching circuit 1100 may include: a switch SWH1 to control thesupply of the turn-on gate voltage (VGH) to the shift register 1410; aswitch SWH2 to control the supply of the voltage (VGH+VLFD) of theturn-on gate voltage (VGH) plus the amplitude (VLFD) of the TDS to theshift register 1410; a switch SWL1 to control the supply of the turn-offgate voltage (VGL) to the shift register 1410; and a switch SWL2 tocontrol the supply of the voltage (VGL+VLFD) of the turn-off gatevoltage (VGL) and the amplitude (VLFD) of the TDS to the shift register1410.

The turn-on gate voltage (VGH), the voltage (VGH+VLFD) of the turn-ongate voltage (VGH) plus the amplitude (VLFD) of the TDS, the turn-offgate voltage (VGL), and the voltage (VGL+VLFD) of the turn-off gatevoltage (VGL) plus the amplitude (VLFD) of the TDS may be supplied froma PMIC 1110 to the switching circuit 1100.

Using the switching circuit 1100, it is possible to select the fourvoltages (VGH, VGH+VLFD, VGL, and VGL+VLFD) needed to generate a gatesignal swinging according to a TDS as necessary. Accordingly, gatesignals having the four voltages (VGH, VGH+VLFD, VGL, and VGL+VLFD) maybe generated.

As described above, the present embodiments may provide a touch displaydevice 100, a method for driving the same, a driving circuit 1300, adata-driving circuit 120, and a gate-driving circuit 130 which enablehigh-speed image display and high-speed touch sensing.

Also, the present embodiments may provide a touch display device 100, amethod for driving the same, a driving circuit 1300, a data-drivingcircuit 120, and a gate-driving circuit 130 which enable a displayoperation and a touch operation to be performed simultaneously.

Further, the present embodiments may provide a touch display device 100,a method for driving the same, a driving circuit 1300, a data-drivingcircuit 120, and a gate-driving circuit 130 which enable an image to bedisplayed normally without any change in the image, while performing adisplay operation and a touch operation simultaneously.

In addition, the present embodiments may provide a touch display device100, a method for driving the same, a driving circuit 1300, adata-driving circuit 120, and a gate-driving circuit 130 which enable adisplay operation and a touch operation to be simultaneously performedwhen driving a high-resolution display.

The above description and the accompanying drawings provide an exampleof the technical idea of the present invention for illustrative purposesonly. Those having ordinary knowledge in the technical field, to whichthe present invention pertains, will appreciate that variousmodifications and changes in form, such as combination, separation,substitution, and change of a configuration, are possible withoutdeparting from the essential features of the present invention.Therefore, the embodiments disclosed in the present invention areintended to illustrate the scope of the technical idea of the presentinvention, and the scope of the present invention is not limited by theembodiment. The scope of the present invention shall be construed on thebasis of the accompanying claims in such a manner that all of thetechnical ideas included within the scope equivalent to the claimsbelong to the present invention.

What is claimed is:
 1. A touch display device comprising: a displaypanel in which a plurality of data lines, a plurality of gate lines, anda plurality of touch electrodes are disposed; a gate-driving circuitconfigured to output a gate signal for driving the plurality of gatelines; a data-driving circuit configured to output a data signal fordriving the plurality of data lines; and a touch-driving circuitconfigured to output a touch-driving signal in order to drive theplurality of touch electrodes while the plurality of data lines and theplurality of gate lines are driven, wherein the touch-driving circuitoutputs a touch-driving signal swinging with a predetermined amplitude,and the data-driving circuit outputs a data signal having a voltagechanged by the amplitude of the touch-driving signal during a high-levelperiod of the touch-driving signal.
 2. The touch display device of claim1, wherein the data-driving circuit outputs a data signal having avoltage of a data voltage corresponding to input digital image data plusthe amplitude of the touch-driving signal during the high-level periodof the touch-driving signal.
 3. The touch display device of claim 1,wherein the data-driving circuit comprises: a digital-to-analogconverter (DAC) configured to convert digital image data into an analogvoltage and to output the analog voltage using gamma voltages; and anoutput buffer configured to output the data signal to the data linesbased on the analog voltage, the gamma voltages swing with the amplitudeof the touch-driving signal, and the analog voltage swings in accordancewith the gamma voltages.
 4. The touch display device of claim 3, furthercomprising a gamma generation circuit configured to generate the gammavoltages, wherein the gamma generation circuit comprises: a first-stageamplifier circuit comprising an upper amplifier having an input node towhich an upper DC voltage is input, coupled with a signal swinging withthe amplitude of the touch-driving signal, through a capacitor, and alower amplifier having an input node to which a lower DC voltage isinput, coupled with a signal swinging with the amplitude of thetouch-driving signal through the capacitor; and a first-stage resistorstring configured to be connected to an output node of the upperamplifier and an output node of the lower amplifier and to have resistorconnection points from which the gamma voltages are output.
 5. The touchdisplay device of claim 3, further comprising a gamma generation circuitconfigured to generate the gamma voltages, wherein the gamma generationcircuit comprises: a first-stage amplifier circuit comprising an upperamplifier having an input node to which an upper DC voltage is input,coupled with a signal swinging with the amplitude of the touch-drivingsignal, through a capacitor, and a lower amplifier having an input nodeto which a lower DC voltage is input, coupled with a signal swingingwith the amplitude of the touch-driving signal through the capacitor; afirst-stage resistor string configured to be connected to an output nodeof the upper amplifier and an output node of the lower amplifier; asecond-stage amplifier circuit comprising amplifiers having an inputnode connected to resistor connection points of the first-stage resistorstring; and a second-stage resistor string configured to be connected tooutput nodes of the amplifiers comprised in the second-stage amplifiercircuit and to have resistor connection points from which the gammavoltages are output.
 6. The touch display device of claim 1, wherein thegate-driving circuit outputs a gate signal having a voltage changed bythe amplitude of the touch-driving signal during the high-level periodof the touch-driving signal.
 7. The touch display device of claim 6,wherein, during the high-level period of the touch-driving signal, thegate-driving circuit outputs a gate signal having a voltage of a turn-ongate voltage plus the amplitude of the touch-driving signal to a gateline corresponding to a turn-on time among the plurality of gate linesand outputs a gate signal having a voltage of a turn-off gate voltageplus the amplitude of the touch-driving signal to a gate linecorresponding to a turn-off time among the plurality of gate lines. 8.The touch display device of claim 1, wherein the gate-driving circuitoutputs a plurality of pulses to one gate line during a one-frameperiod.
 9. The touch display device of claim 8, wherein, during theone-frame period, one pulse among the plurality of pulses has a voltageof a turn-on gate voltage plus the amplitude of the touch-drivingsignal, and remaining pulses among the plurality of pulses have avoltage of a turn-off gate voltage plus the amplitude of thetouch-driving signal.
 10. The touch display device of claim 1, whereinthe gate-driving circuit, through a switching circuit, outputs a gatesignal based on one selected from among a turn-on gate voltage, avoltage of the turn-on gate voltage plus an amplitude of thetouch-driving signal, a turn-off gate voltage, and a voltage of theturn-off gate voltage plus the amplitude of the touch-driving signal.11. The touch display device of claim 1, wherein the plurality of touchelectrodes is a common electrode forming a capacitor along with a pixelelectrode.
 12. A method for driving a touch display device comprising adisplay panel in which a plurality of data lines, a plurality of gatelines, and a plurality of touch electrodes are disposed, a gate-drivingcircuit configured to drive the plurality of gate lines, and adata-driving circuit configured to drive the plurality of data lines,the method comprising: outputting a touch-driving signal in order todrive the plurality of touch electrodes while the plurality of datalines and the plurality of gate lines are driven; and detectingoccurrence of a touch or coordinates of a touch based on a signalreceived through each touch electrode, wherein in the outputting thetouch-driving signal, the touch-driving signal swings with apredetermined amplitude, and a data signal to drive the data lines has avoltage changed by the amplitude of the touch-driving signal during ahigh-level period of the touch-driving signal.
 13. The method of claim12, wherein a gate signal to drive the gate lines has a voltage changedby the amplitude of the touch-driving signal during a high-level periodof the touch-driving signal.
 14. A data-driving circuit for driving adisplay panel in which a plurality of data lines and a plurality oftouch electrodes are disposed, the data-driving circuit comprising: adigital-to-analog converter (DAC) configured to convert digital imagedata into an analog voltage and to output the analog voltage, usinginput gamma voltages; and an output buffer configured to output a datasignal to the data lines based on the analog voltage, wherein the datasignal is output while the touch electrodes are driven and has a voltagechanged by an amplitude of a touch-driving signal during a high-levelperiod of the touch-driving signal.
 15. The data-driving circuit ofclaim 14, wherein the gamma voltages swing with the amplitude of thetouch-driving signal.
 16. A driving circuit for driving a display panelin which a plurality of data lines and a plurality of touch electrodesare disposed, the driving circuit comprising: a data-driving circuitconfigured to drive the plurality of data lines; and a touch-drivingcircuit configured to drive the plurality of touch electrodes, whereinthe touch-driving circuit drives the plurality of touch electrodes whilethe plurality of data lines is driven, and outputs a touch-drivingsignal swinging with a predetermined amplitude to drive the touchelectrodes, and the data-driving circuit outputs a data signal having avoltage changed by the amplitude of the touch-driving signal during ahigh-level period of the touch-driving signal.
 17. A gate-drivingcircuit for driving a display panel in which a plurality of gate linesand a plurality of touch electrodes are disposed, the gate-drivingcircuit comprising: a shift register configured to generate a gatesignal synchronized with a clock; a level shifter configured to converta signal voltage amplitude of the gate signal generated in the shiftregister; and an output buffer configured to output the gate signal withthe converted signal voltage amplitude, wherein the gate signal outputfrom the output buffer has a voltage changed by an amplitude of atouch-driving signal during a high-level period of the touch-drivingsignal for driving the touch electrodes.
 18. The gate-driving circuit ofclaim 17, further comprising: a switching circuit configured to selectone of a turn-on gate voltage, a voltage of the turn-on gate voltageplus the amplitude of the touch-driving signal, a turn-off gate voltage,and a voltage of the turn-off gate voltage plus the amplitude of thetouch-driving signal and to supply the selected voltage to the shiftregister.